JP2009224285A - Circuit breaker unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit breaker unit having a leak detector in which a testing unit for testing to confirm the operation of the leak detector can be constituted without using resistors with a high rated power and heat resistivity at a low price with a small-sized structure; with reduced possibility of heating by testing operation, possibility of disconnection and burnout of wires in accordance with the heating, and influence by heat over peripheral components; and moreover with reduced power loss caused by the testing operation. <P>SOLUTION: The current breaker unit is provided through cable channels. The unit includes a zero-phase current transformer to output an induced current to a secondary winding, when an imbalanced current is generated in the cable channel; a controller to which a current signal outputted from the secondary winding is converted to a voltage signal, and inputted to generate a leak detecting signal when the voltage signal is larger than a predetermined level; and a testing unit having a test switch and an impedance comprising a capacitor to output the induced current to the secondary winding. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a circuit breaker provided with a leakage detection unit that detects a leakage current in an AC circuit or equipment and outputs a leakage detection signal when the leakage current reaches a predetermined magnitude. In particular, the present invention relates to a circuit breaker provided with a test device section for testing the operation of the leakage detection section.

As a test apparatus provided for testing the operation of the leakage detection unit, for example, there is one disclosed in Patent Document 1. FIG. 9 shows a circuit configuration of Patent Document 1.

In FIG. 9, 1 is a main circuit, 2 is a switching contact for opening and closing the main circuit 1, 3 is a zero-phase current transformer through which the main circuit 1 penetrates and a secondary winding 3a and a test winding 3b are wound. 4 is a control circuit in which the input side is connected between both ends of the secondary winding 3a of the zero-phase current transformer 3, 7 is a rectifier circuit for supplying power to the control circuit 4, and the AC side of the clear current circuit is It is connected to the main circuit 1 via the voltage drop element 8.

Reference numeral 5 denotes a thyristor controlled by the output of the control circuit 4. The anode of the thyristor 5 is connected to the main circuit 1 together with a voltage drop element 8 connected to one end on the AC side of the rectifier circuit 7 via an electromagnetic trip device 6. The gate of the thyristor is connected to the output side of the control circuit 4, and the cathode of the thyristor 5 is connected to the low voltage side of the control circuit 4.

The electromagnetic trip device 6 is mechanically linked to the switching contact 2, and when the thyristor 5 is turned on by the output of the control circuit 4 and the electromagnetic trip device 6 is excited, the switching contact 2 is opened. The main circuit 1 is configured to be opened.

The high voltage side and low voltage side of the power supply of the control circuit 4 are connected to the DC side of the rectifier circuit 7 respectively.
Reference numeral 9 is a test switch, and 10 is a test resistor, which are connected in series with each other and connected to the main circuit 1 via the test winding 3b of the zero-phase current transformer 3.

When the test switch 9 is closed, a predetermined current flows from the AC power source of the main circuit 1 through the test switch 9 and the test resistor 10 to the test winding 3b of the zero-phase current transformer 3, thereby causing the secondary winding 3a to flow. An output voltage similar to that described above is generated, and the electromagnetic trip device 6 is excited by the control circuit 4 and the thyristor 5 to open the circuit breaker 2.

As described above, in order to perform an operation test in a circuit breaker, it is a common practice to perform an operation test by passing a current of a predetermined magnitude through the test winding using the test winding 3b. It is that you are. In addition, when a current of the predetermined magnitude is supplied to the test winding 3b, the test resistor 10 is generally used for the purpose of limiting the current from the main circuit 1.

Japanese Patent Laid-Open No. 5-182579 FIG.

In the case of a circuit breaker, if the leakage detection is not performed, there is a risk of an electric shock accident or a night fire due to the leakage current. However, when performing such a test operation, the following problems arise. First, since the same voltage as the phase voltage of the main circuit to which the test resistor is connected is applied to the test resistor, it is necessary to use a test resistor having a large rated power as a whole. That is, if the interphase voltage of the main circuit to which the test resistor is connected is 100 V and the current required for the test operation is 1 A, it is necessary to use at least a resistance component with a rated power of 1 W. Similarly, the main circuit to which the test resistor is connected When the interphase voltage is 200 V and the current required for the test operation is 1 A, it is necessary to use at least a resistance component with a rated power of 2 W.

In addition, the resistor has a large power loss, and when selecting a component with the safety factor in mind, it is necessary to use a resistor component with a larger rated power as the resistor component that satisfies the above-mentioned performance, resulting in an increase in the outer shape. There was a problem of requiring a lot of installation space.

In addition, when the test operation is performed continuously or when a voltage is accidentally applied continuously, the resistance component generates heat, which causes the wire to break or the test resistance to burn out. There is a problem in that it may affect the possibility of reaching or the parts arranged around the test part. In addition, the test operation is repeated as appropriate, and even if the power required for the test operation in each circuit breaker is small, the total power used is large because the number increases nationwide. Therefore, it is desirable that the power consumed for the test operation is as low as possible from the viewpoint of effective use of resources and environmental protection.

In addition, a resistor with a large rated power or a resistor with high heat resistance has a problem of high cost.

In view of this, the present invention provides a circuit breaker having a leakage detection unit for detecting a leakage current flowing in an AC circuit, equipment, etc. with a test device unit for confirming the operation of the leakage detection unit having a rated power and heat resistance performance. It can be configured inexpensively and compactly without using high-resistance components, and it can reduce the heat generated by the test operation, the possibility of wire breakage and burnout, and the effects of heat on the surrounding components. Moreover, it is an object of the present invention to provide a circuit breaker including a test device unit that can reduce power consumed for a test operation.

In order to achieve the above-mentioned object, according to claim 1 of the present invention, a zero-phase change is provided that penetrates an electric circuit and outputs an induced current to the secondary winding when an unbalanced current is generated in the electric circuit. A control device that generates a leakage detection signal when the current signal output from the secondary winding is converted into a voltage signal and is input, and the magnitude of the voltage signal is equal to or greater than a predetermined value; The present invention provides a circuit breaker characterized in that the circuit breaker is configured to include a test device including an impedance composed of a capacitor for outputting an induced current to the winding and a test switch.

According to such a circuit breaker, during the test operation of the leakage detector comprising the zero-phase current transformer and the control device, a current flows through the impedance formed by the capacitor, so that the current advanced by 90 ° from the voltage phase. As a result, the test operation with reactive current that does not involve the consumption of electrical energy is performed. For this reason, the power consumption and heat generation associated with the test operation can be reduced as much as possible, and a safe and inexpensive circuit breaker can be provided that can be configured using inexpensive and small components without using resistive components with high rated power and high heat resistance. can do.

In addition, the test device is connected to the first phase in the circuit and the power source side of the zero-phase current transformer, and is connected to a phase different from the first phase and the load side of the zero-phase current transformer. When the impedance is electrically connected between the phases by operating the test switch, an unbalanced current is generated in the electric circuit, so that an induced current is output to the secondary winding. A circuit breaker may be provided.

As a result, the power consumption and heat generation associated with the test operation can be reduced as much as possible and the rated power and heat resistance performance are high when the test wires are arranged not to penetrate the zero-phase current transformer for the test operation. It is possible to provide a safe and inexpensive circuit breaker that can be configured using inexpensive and small components without using resistive components.

The test device is connected to a tertiary winding provided in the zero-phase current transformer, and when the impedance is electrically connected to the tertiary winding by operating the test switch, the tertiary winding A circuit breaker characterized in that when a current of a predetermined magnitude is applied to the wire with the impedance, an induced current is generated in the zero-phase current transformer and an induced current is output to the secondary winding. May be provided.

As a result, when the test current is output to the tertiary winding of the zero-phase current transformer for the test operation, the power consumption and heat generated by the test operation can be reduced as much as possible, and the rated power and heat resistance performance are high. It is possible to provide a safe and inexpensive circuit breaker that can be configured using inexpensive and small components without using resistive components.

The impedance may further comprise a resistor connected in series with the capacitor, and a circuit breaker may be provided.

As a result, when performing a test operation, it is possible to provide a circuit breaker that can suppress an inrush current flowing through the test apparatus and can maintain a long-term service life of the components used.

The impedance may further include a coil connected in series with the capacitor, and a circuit breaker may be provided.

This provides a circuit breaker that can suppress the inrush current that flows to the test equipment, maintain the aging life of the components used for a long time, and further reduce power consumption when performing test operations. can do.

In addition, a circuit breaker may be provided in which the capacitance of the capacitor used as the impedance is 1.0 × 10 ⁻³ μF to 1.59 × 10 ³ μF.

As a result, it is possible to provide a circuit breaker that can cover a wide range of differences in commercial frequency and voltage of the electric circuit, from a high sensitivity to a low sensitivity of the leakage current.

According to the circuit breaker of the present invention, in a circuit breaker having a leakage detection unit for detecting a leakage current flowing in an AC circuit or equipment, a test device for confirming the operation of the leakage detection unit is provided with a rated power or It can be configured inexpensively and compactly without using resistance parts with high heat resistance, and it is possible to minimize the heat generated by the test operation, the possibility of wire breakage or burning caused by the heat generation, and the influence of the heat on surrounding components. It is possible to provide a circuit breaker including a test device that can reduce power consumption for the test operation.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In all of the embodiments, a ground fault generated in an AC circuit of commercial frequency is detected, and when a ground fault of a predetermined size occurs, a ground fault circuit breaker that interrupts the circuit, and a ground of a predetermined size are provided. When a fault has occurred, a circuit breaker with a leakage alarm signal output function that allows the outside to recognize that a ground fault has occurred, or a function to notify the surroundings by sound or light that a ground fault has occurred It shows about the circuit breaker for wiring.

Further, the AC circuit is assumed to be a residential or industrial circuit such as a three-phase three-wire circuit, a three-phase four-wire circuit, a single-phase three-wire circuit, a single-phase two-wire circuit, or the like. In the drawings, substantially the same parts are denoted by the same reference numerals.

(First embodiment)
As a first embodiment, FIG. 1 shows a circuit breaker 1000 applied to a single-phase two-wire electric circuit.

In FIG. 1, reference numeral 1 denotes an AC circuit, and a zero-phase current transformer 102 is disposed through the AC circuit 1. The zero-phase current transformer 102 is provided with a secondary winding 1021 for output. When an unbalanced current is generated in the AC circuit 1, it is generated according to the magnitude of the unbalanced current. The induced current is output from the secondary winding 1021.

The secondary winding 1021 is input to the control device 101 that determines whether or not a leakage has occurred. A resistance for converting the induced current into a voltage signal is provided at the end of the secondary winding 1031. The control device 101 can be controlled by the magnitude of the voltage signal input from the secondary winding 1021. It is determined whether or not a leakage current has occurred. If it is determined that a leakage current has occurred, a leakage detection signal is output. The control device 101 is configured by using a generally used leakage IC.

In addition, it replaces with earth-fault IC as control apparatus 101, is comprised using a microcomputer, A / D-converts the said input voltage signal, the voltage data after conversion, and the threshold value data predetermined in the microcomputer A comparison operation may be performed, and a leakage detection signal may be output when the voltage data exceeds the threshold data.

Reference numeral 301 denotes a thyristor to which the leakage detection signal is input as a trigger signal. A trip coil 302 is connected to the anode side of the thyristor 301, and an end of the trip coil is connected to an electric circuit. Further, the cathode side of the thyristor 301 is connected to an electric circuit having a phase different from that of the electric circuit to which the trip coil is connected.

The trip coil 302 is mechanically linked to the contact switching mechanism of the circuit breaker 1000. When the leakage detection signal is input, the thyristor 301 is turned on and connected between the lines of the electric circuit. When a current flows through the trip coil 302, the trip coil operates and acts on the contact opening / closing mechanism to cut off the electric circuit.

The leakage detection unit 100 includes the above-described zero-phase current transformer 102, secondary winding 1021, and control device 101.

Further, the circuit breaker 1000 is provided with a test device 200 that outputs an induced current to the secondary winding 1021. The test apparatus 200 connects an impedance 202 made of a capacitor and a test switch 201 on the power source side of the first phase in the electric circuit and the zero-phase current transformer 102 and has a phase different from the first phase. The zero-phase current transformer 102 is connected on the load side.

When the impedance 202 is electrically connected between the phases of the electric circuit by operating the test switch 201, an unbalanced current is generated in the electric circuit, so that an induced current is output to the secondary winding 1021. The As a result, the induced current is converted into a voltage by a resistor provided at the end of the secondary winding 1021, and the control device 101 determines that a leakage current has occurred and outputs a leakage detection signal.

Here, the capacitance of the impedance is determined so that the magnitude of the test current that flows when the test switch 201 is operated is 2.5 times or less the sensitivity current of the circuit breaker 1000. The magnitude of the test current is determined by various factors, and is caused by the voltage between the phases of the circuit, the frequency of the power source of the circuit, the sensitivity current, and the safety factor.

Here, “Table 1” shows the impedance capacity when the voltage between the phases of the circuit, the frequency of the power source, and the sensitivity current are variables. The impedance when a capacitor is used is
Z = 1 / 2πfC (Expression 1), and the current flowing in this case is I = V / Z.
C = I / 2πfV (Expression 2)
Here, I is a sensitivity current, 5 mA to 20 A, f is a frequency, 50 or 60 Hz, V is a voltage between phases, and an impedance capacity is shown as 100 or 200 V.

Table 1

Thus, it is recommended to use a capacitor with a capacity of 1.7 × 10 ⁻¹ μF to 1.59 × 10 ³ μF depending on the sensitivity current, the voltage between phases, and the frequency. When the safety factor is expected, for example, if the safety factor is twice, it is preferable to use capacitors each having a doubled capacity.

(Second Embodiment)
As a second embodiment, FIG. 2 shows a circuit breaker applied to a single-phase two-wire electric circuit. The difference from the first embodiment is that the test current output by the test apparatus is not directly applied to the electric circuit.

In FIG. 2, reference numeral 1 denotes an AC circuit, and a zero-phase current transformer 102 is disposed through the AC circuit 1. The zero-phase current transformer 102 is provided with a secondary winding 1021 for output. When an unbalanced current is generated in the AC circuit 1, it is generated according to the magnitude of the unbalanced current. The induced current is output from the secondary winding 1021.

The secondary winding 1021 is input to the control device 101 that determines whether or not a leakage has occurred. A resistance for converting the induced current into a voltage is provided at the end of the secondary winding 1021, and the control device 101 has a leakage current depending on the magnitude of the voltage input from the secondary winding 1021. It is determined whether or not a leakage current has occurred, and when it is determined that a leakage current has occurred, a leakage detection signal is output. The control device 101 is configured by using a generally used leakage IC.

In addition, as described above, the control device 101 is configured using a microcomputer instead of the leakage IC, and the input voltage signal is A / D converted, and the converted voltage data and the microcomputer are predetermined in the microcomputer. The threshold value data may be compared and calculated, and when the voltage data exceeds the size of the threshold value data, a leakage detection signal may be output.

The trip coil 302 is mechanically interlocked with the contact switching mechanism of the circuit breaker 1000. When the leakage detection signal is input, the thyristor 301 is turned on and connected between the lines of the electric circuit. When a current flows through the trip coil 302, the trip coil 302 operates and acts on the contact opening / closing mechanism, thereby interrupting the electric circuit.

The circuit breaker 1000 is provided with a test device 200 that outputs an induced current to the secondary winding 1021. The test apparatus 200 is provided with an impedance 202 composed of a capacitor connected to a power source connected to a tertiary winding 1022 provided in the zero-phase current transformer 102 via a test switch 201. In addition, you may comprise so that the power supply of a test apparatus may be acquired from an alternating current circuit.

When the impedance 202 is electrically connected to the tertiary winding 1022 by operating the test switch 201, a current of a predetermined magnitude is output from the capacitor to the tertiary winding 1022, thereby An induced current is generated in the phase current transformer 102, and as a result, the induced current is output to the secondary winding 1021.

Here, the capacitance of the impedance is determined so that the magnitude of the test current that flows when the test switch 201 is operated is 2.5 times or less the sensitivity current of the circuit breaker 1000. The magnitude of the test current is determined by various factors, and when power is obtained from the circuit, it depends on the voltage between phases, the frequency of the circuit power, the sensitivity current, the number of turns of the tertiary winding, the safety factor, etc. To do.

Here, “Table 2” shows the impedance capacity when the voltage between the phases of the circuit, the frequency of the power source, and the sensitivity current are variables. The impedance when a capacitor is used is
Z = 1 / 2πfC (Expression 1), and the current flowing in this case is I = V / Z.
C = I / 2πfV (Expression 2)
Where I is the sensitivity current, 5 mA to 20 A, f is the frequency, 50 or 60 Hz, V is the voltage between the phases, 100 or 200 V, N is the number of turns of the tertiary winding, and the impedance is 1 to 100 times. Showed capacity.

表２−２

表２−３

表２−４

Table 2-1.

Table 2-2

Table 2-3

Table 2-4

Thus, it is recommended to use a capacitor with a capacity of 1.7 × 10 ⁻³ μF to 1.59 × 10 ³ μF depending on the sensitivity current, the voltage between phases, the frequency, and the number of turns of the tertiary winding. When the safety factor is expected, for example, if the safety factor is twice, it is preferable to use capacitors each having a doubled capacity.

Further, since the cost of the zero-phase current transformer increases as the number of turns of the tertiary winding increases, the number of turns of about 20 to 50 is preferable. In this case, 1.3 × 10 ⁻³ μF to 8.0 × 10 ¹ Use a capacitor with a capacitance of μF.

In addition, when a circuit breaker installed in a household or industrial circuit is used for a more general sensitivity current, a capacity of 1.0 × 10 ⁻² μF to 1.99 μF corresponding to a sensitivity current of 15 mA to 500 mA. It is recommended to use the capacitor.

In addition, the capacitance of the capacitor should be determined appropriately according to the conditions such as the electric circuit using the circuit breaker and the sensitivity current.

(Third embodiment)
As a third embodiment, FIG. 3 shows a circuit breaker applied to a single-phase two-wire electric circuit. This embodiment differs from the first embodiment in that a capacitor 202 and a resistor 203 connected in series with the capacitor are used as the impedance provided in the test apparatus 200.

In the case of using only a resistor as the impedance, the resistance value is, for example, 10 kΩ when the voltage between phases of the electric circuit is 200 V and the required current is 20 mA. The required rated power is 4W. For this reason, it is necessary to use a resistance component having a safety factor of at least 4 W and a resistance value of 10 kΩ or more.

When a capacitor and a resistor are used as impedance as in the third embodiment, the purpose of using the resistor is to suppress inrush current. When the resistance value is zero, the instantaneously flowing current is as large as a short-circuit current, which may affect the capacitor. For example, when a resistance of about 300Ω is used, the inrush current is 0.6 A. The current value can be suppressed to a level that does not affect the capacitor. Also, since the voltage value is divided by the capacitor and the resistor, the voltage value applied to each component is relatively small, and the required rated power can be reduced.

In this way, as the resistance value, it is only necessary to use a resistance component of about 1/30 of 10 kΩ, and the rated power may be small. The external size of the resistor component can be reduced.

(Fourth embodiment)
As a fourth embodiment, FIG. 4 shows a circuit breaker applied to a single-phase two-wire electric circuit. The second embodiment differs from the second embodiment in that a capacitor 202 and a resistor 203 connected in series with the capacitor are used as the impedance provided in the test apparatus 102.

Even in this case, as described above, for example, a resistance component having a resistance value of about 1/30 of 10 kΩ may be used as compared with the case of using only a resistance as an impedance. In addition, since the rated power may be small, the outer size of the resistor component to be used can be reduced as compared with the case where only the resistor is used as the impedance. In addition, since heat generation is small, the influence on surrounding parts can be reduced.

(Fifth embodiment)
As a fifth embodiment, FIG. 5 shows a circuit breaker applied to a single-phase two-wire electric circuit. The third embodiment is different from the third embodiment in that a coil 204 connected in series with a capacitor 202 is used instead of the resistor 203 as the impedance provided in the test apparatus 200.

Since the resistor is used in the third embodiment, the power consumption accompanying the test operation is not a little generated. For this reason, power consumption can be further reduced by connecting a coil.

Further, when the capacitor 202 and the coil 204 are used as the impedance as in the fifth embodiment, the purpose of using the coil is to suppress the inrush current.

When the resistance value is zero, the instantaneously flowing current is about the magnitude of the short-circuit current between phases, which may affect the capacitor. For example, if a coil with an inductance of about 100 mH to 500 mH is used, it will rush The current can be suppressed to a current value of several A, which does not affect the capacitor. Also, since the voltage value is divided by the capacitor and the resistor, the voltage value applied to each component is relatively small, and the required rated power can be reduced.

As described above, when a capacitor and a coil are used as the impedance, the size of the impedance component to be used can be reduced, and the power consumption accompanying the test operation can be further reduced.

(Sixth embodiment)
As a sixth embodiment, FIG. 6 shows a circuit breaker applied to a single-phase two-wire electric circuit. The fourth embodiment is different from the fourth embodiment in that a coil 204 connected in series with a capacitor 202 is used instead of the resistor 203 as the impedance provided in the test apparatus 200.

Even in this case, as described above, the power consumption can be further reduced as compared with the case where the capacitor 202 and the resistor 203 are used as the impedance, and the influence on surrounding components can also be reduced.

(Seventh embodiment)
As a seventh embodiment, FIG. 7 shows a circuit breaker applied to a single-phase two-wire electric circuit. The circuit breaker of the present embodiment is a circuit breaker with a leakage alarm function that performs a leakage alarm without having the leakage breaker 300. In the first embodiment, an output signal from the leakage detection unit 100 is not input to the thyristor 301 described above, but is output and processed toward a leakage relay or leakage alarm device provided outside. It is different in point.

In this case, it is possible to provide a circuit breaker having a leakage alarm signal output function for recognizing the occurrence of a ground fault when a ground fault of a predetermined size occurs. In the circuit breaker that performs the leakage alarm, the circuit breaker body is provided with a notification means for receiving the leakage alarm output signal and informing the surroundings by sound or light that the ground fault has occurred. , A test device that can reduce the heat generated by the test operation, the possibility of wire breakage and burnout, and the influence of the heat on the surrounding parts, and the power consumed for the test operation It becomes possible to provide the circuit breaker provided with.

(Eighth embodiment)
FIG. 8 shows a circuit breaker applied to a single-phase two-wire circuit. The circuit breaker of the present embodiment is a circuit breaker with a leakage alarm function that performs a leakage alarm without having the leakage breaker 300. In the second embodiment, the output signal from the leakage detection unit 110 is not input to the thyristor 301 described above, but is output and processed toward a leakage relay or leakage alarm device provided outside. It is different in point.

In this case, as in the seventh embodiment, when a ground fault of a predetermined size occurs, the circuit breaker for wiring having an earth leakage alarm signal output function for recognizing the occurrence of the ground fault to the outside Can be provided.

In the circuit breaker that performs the leakage alarm, the circuit breaker body is provided with a notification means for receiving the leakage alarm output signal and informing the surroundings by sound or light that the ground fault has occurred. , A test device that can reduce the heat generated by the test operation, the possibility of wire breakage and burnout, and the influence of the heat on the surrounding parts, and the power consumed for the test operation It becomes possible to provide the circuit breaker provided with.

Although the embodiment has been described with respect to a single-phase two-wire circuit, the present invention can also be applied to other single-phase three-wire and three-phase three-wire electric circuits. In the case of a wire system, the test current may be supplied to the first voltage phase and the second voltage phase, or the test current may be supplied to the voltage phase and the neutral phase. May be.

The present invention is applied to a circuit breaker that detects a leakage occurring in an electric circuit, whereby the operation of the leakage detection unit is performed in a circuit breaker having a leakage detection unit that detects a leakage current flowing in an AC circuit or equipment. The test equipment for checking can be configured inexpensively and compactly without using rated components with high rated power and high heat resistance, and the heat generated by the test operation and the wire breakage or burnout caused by the heat generation can occur. As a result, it is possible to provide a circuit breaker equipped with a test device capable of reducing the power consumption and the influence of heat on peripheral components as much as possible and reducing the power consumed for the test operation.

The figure which shows the structure of the circuit breaker by 1st Embodiment. The figure which shows the structure of the circuit breaker by 2nd Embodiment. The figure which shows the structure of the circuit breaker by 3rd Embodiment. The figure which shows the structure of the circuit breaker by 4th Embodiment The figure which shows the structure of the circuit breaker by 5th Embodiment The figure which shows the structure of the circuit breaker by 6th Embodiment The figure which shows the structure of the circuit breaker by 7th Embodiment The figure which shows the structure of the circuit breaker by 8th Embodiment The figure which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric circuit 1000 Circuit breaker 100 Earth leakage detection part 110 Earth leakage detection part 101 Control apparatus 102 Zero phase current transformer 1021 Secondary winding 1022 Tertiary winding 200 Test apparatus part 201 Test switch 202 Capacitor 203 Resistance 204 Coil 300 Earth leakage interruption part 301 Thyristor 302 Trip coil

Claims (6)

A zero-phase current transformer that is provided through the electric circuit and outputs an induced current to the secondary winding when an unbalanced current is generated in the electric circuit;
A control device for generating a leakage detection signal when the current signal output from the secondary winding is converted into a voltage signal and input, and the magnitude of the voltage signal is equal to or greater than a predetermined value;
A test device comprising an impedance consisting of a capacitor for outputting an induced current to the secondary winding and a test switch;
A circuit breaker characterized by comprising:
The test equipment is
The first phase in the electric circuit is connected to the power source side of the zero-phase current transformer, the phase different from the first phase is connected to the load side of the zero-phase current transformer,
When the impedance is electrically connected between the phases by operating the test switch,
2. The circuit breaker provided with a test device according to claim 1, wherein an induced current is output to the secondary winding when an unbalanced current is generated in the electric circuit.
The test equipment is
Connected to the tertiary winding provided in the zero-phase current transformer,
When the impedance is electrically connected to the tertiary winding by operating the test switch,
When a current of a predetermined magnitude is applied to the tertiary winding with the impedance,
An induced current is generated in the zero-phase current transformer,
The circuit breaker according to claim 1, wherein an induced current is output to the secondary winding.
4. The circuit breaker according to claim 2, wherein the impedance further comprises a resistor connected in series with the capacitor.
4. The circuit breaker according to claim 2, wherein the impedance further comprises a coil connected in series to the capacitor.
6. The circuit breaker according to claim 1, wherein a capacitance of the capacitor used as the impedance is 1.0 × 10 ⁻³ μF to 1.59 × 10 ³ μF.

Images